Control of bulkhead-doors.



No. 831,431. PATENTED SEPT. 18-, 1906.

' L. A. HAWKINS.

CONTROL OF BULKHEAD DOORS. APPLICATION FILED IDEO. 29,1905.

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No. 831,431 I PATENTED SEPT. 18, 1906. L. A. HAWKINS. CONTROL OF BULKHEAD DOORS.

APPLICATION TILED DEOHZQ, 1905.

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$24M ajm/ I MA fl UNITED STATES. PATENT OFFICE- LAURENCE A. HAWKINS, OF SGHENECTADY, NEW YORK, ASSIGNOR TO. GENERAL ELECTRIC COMPANY, A CORPORATIONOF NEW YORK.

CONTROL OF BULKHEAD-DOORS.

Specification of Letters Patent.

Patented Sept. 18,1906.

Application filed December 29. 1905. Serial No. 293,852-

I head-Doors, of which. the following is a specification.

My invention relates to switches for electric systems of distribution, and is particularly applicable to electrically-operated bulkhead-door systems and will consequently be described in connection with such a system, although in its broadest aspect it is not limited to this particular application.

Electrically-operated bulkhead-door systems have been arranged. heretofore with means at each door for controlling the movement of the door and distant controlling means whereby all the doors may be con trolled from a single point. For this pur pose it is customary to group the distant controlling means for a plurality of doors in a single control-circuit, the control system comprising a plurality of these control-circuits. Thus by energizing any one of the control-circuits all the doors which have their controlling means connected in that circuit will be operated. In case of an emergency it may be important to close all the doors on a ship in as short a time as possible. On the other hand, if all the control-circuits were closed at once a heavy overload would ordinarily be thrown upon the generator, which might trip the main circuit-breaker or in other ways interfere with the proper operation of the devices supplied from the generator.

The object of my invention is to provide means for closing the doors as rapidly as possible without overloading the generator. I accomplish this by providing a plurality of independently-movable switches for connectingthe several control-circuits to the source of'current and automatic means for preventing the closing of any switches when the sum of the currents in the control-circuits exceeds a predetermined amount. Thus, for

instance, if all the control-circuits are open the operator'can close one control-switch after another until the maximum allowable load on the-system is-reached. At this point the automatic means will prevent the closing of anymore switches until some of the load is removed from the control-circuits already energized. As soon as this load is removed the operator is free to close more switches.

In this way the maximum allowable output is obtained all the time without overloading the system.

In order to obtain the maximum advantage from my invention, it is desirable to employ means at the several doors for disconnecting the distant controlling means from the control-circuit when the dooris closed. In this way the load on anyone control-circuit corresponds only to the useful work that is being done on the doors controlled from that circuit, so that the maximum useful work without overloading the generator is obtained.

My invention will best be understood by reference to the accompanying drawings, in which- Figure 1 represents a side elevation of a bulkhead-door of a type to which my invention is applicable. Fig. 2 represents a front elevation of the same. Fig. 3 is a diagram of the control-circuit, and Fig. 4 shows the arrangement of the control-switches and 8e automatic controlling means therefor.

, In Figs. 1 and 2, A represents a watertight bulkhead provided with a verticallymovable door B. This door is arranged to be opened and closed by an electric-motor M,- which carries on its shaft a worm d, engaging a worm-wheel D, which is connected through a pinion e to a vertical rack E on the door. As the motor rotates in one direction or theother the door will be opened or closed.

1 0 represents the controlling-switch for the motor, which is provided with an operating shaft and hand-wheels on either side of the bulkhead, so that the switch may be moved to raising or lowering osition byaman on .95 either side of the bulk ead. The controller C is also provided with an operating-magnet m, by means of which the controller may be moved to lowering position from the distant station. The arrangement of the controlling.- switch and its ope rating-magnetforms no part of my present invention and may be constructed in any suitable manneras, for. instance, in the manner disclosed in my former patent, No. 787,293, dated April 11, 105 1905. It is only essential for the understanding of my present invention that it be understood that when the magnet m is energized the control-switch C is moved into proper position to connect the motor for lowering the door.

The shaft of the motor M carries a collar f, which is adapted to engage a stationary yoke F, sliding on guide-rods G and normally held in the position shown by the compressionsprings g. The yoke F is connected, through a bell-crank lever h, to a pivoted switch H, which is connected in series with the magnet m. When an abnormal resistance is opposed to the movement of the door-as, for instance, when the door reaches the lower limit of its travel or when it strikes a piece of coal in closing-the increased end thrust on the motor-shaft received from the worm d prelsi ses the yoke F towarfi the left as viellved in i 1, com ressin t e s rin ,roc in the hell-crank? lever h, an d oie ning thi switch H, thereby denergizing the magnet m and allowing the controlling-switch C to go to off position. In this way whenever the door is stopped and the motor is doing no useful work the controlling-magnet m is cut off from the control-circuit.

The control-circuit connections are shown diagrammatically in Fig. '3. In this figure, I represents the source of current which supplies the operating-motors M to M through the' controlling-switches O to 0, respectively. L represents the control leads or circuits from the distant station, including the controlling-magnets for the motorswitches. The magnets m and 'm are represented as connected to one lead L, while the magnets m and'm are connected to another lead.

II to H represent the switches, which are controlled by the end thrusts on the motorshafts, as has been heretofore explained, and which are open when the door is closed. Consequently in the diagram the doors operated by the motors M and M are open, while the doors M and M are closed.

S represents the controllin -switches at the distant control-station. T ese switches are independently movable and each is arran ed to connect one of thecontrol-circuits to t e source of current. I

0 represents an overload-magnet which is connected in circuit between the source of current and the'switches, so that it is energized by a current equal to the sum of the currents in all the control-circuits. The ma net 0 is suitably connected to a rocksha t R, which extends past the row of switches and which carries a number of latches which are arranged to project into the path of movement of the several switches when the rock-shaft is moved by the magnet.

The operator at the control-station'may close one switch after another until the predetermined load limit is reached. Since only the control-magnets of the doors which are'open are connected to any of the controlcircuits, the motors for the doors that are closed are not connected to the source of current when the control-circuits are closed, and consequently the'system is not loaded by motors which are doing no useful work. The number of, controlling-magnets the circuits of which are closed corresponds to the number of motors which are at any time operated, and consequently the sum of the currents in the control-circuits represents the load which the generator I is at any time sup lying.

en in closing the control-switches the maximum allowable load is reached, the operating-magnet prevents the closing of any more switches, as has been heretofore explained; but as soon as any door closes its controlling-magnet is cut out of circuit, thereby cutting out its motor and decreasing the load both on the control-circuit and on the motor-circuit. When enough doors have been closed and enough control-magnets deenergized to reduce the sum of the currents in the control-circuit below the predetermined amount, the overload-magnet 0 releases its coreand allows more switches to be I closed. In this way it is always possible to load the generator I up to the allowable limit and to keep it thus loaded until all the doors are closed without at any time exceeding this limit.

A suitable arrangement of the controlswitches, overload-magnet, and locking means is shown in Fig. 4. The rock-shaft R carries a number of latches K corres ond-' ing to the several control-switches. hese latches are normally in the position shown in full lines, and consequently do not interfere with the closing of the switches. When the current through the magnet O exceeds a predetermined amount, it draws up its armature 0, thereby straightening out the togglejoint formed by the pivoted levers T and rocking the shaft It. The latches K are then moved to the position indicated by the dotted lines. This brings them into the paths of movement of the switches in closing, and .since there is a latch for every switch it is impossible to close any more switches as long as the latches remain in this position. Whenever the current in the magnet 0 falls below the predetermined limit, the togglejoint is released and the latches drop back to I the position shown in fulllines.

1. Incombination, a plurality of load-cir- 1 0 cuits, a plurality of independently-movable switches adapted to connect said circuits to a source of current, and automatic means for preventing the closing of any of said switches when the sum of the currents in said circuits exceeds a predetermined amount.

2. In combination, a plurality of load-circuits, a plurality of independently-movable switches adapted to connect said circuits to a source of current, a magnet connected in circuit between said source and said switches, and means controlled by said magnet for preventing the closing of said switches.

3. In combination, a plurality of load-circuits, a plurality of independently-movable switches adapted to connect said circuits to a source of current, a magnet energized by a current proportional to the sum of the cur rents in said load-circuits, and means controlled by said magnet for preventing the closing of said switches.

4.. In combination, arow of ind ependentlymovable switches, blocking means adapted to be interposed in the paths of movement of all of said switches, and an overload-magnet controlling said blocking means.

5. In combination, arow of independentlymovable switches, a rock-shaft extending along said row, latches carried by said shaft adapted to project into the paths of movement of said switches when said shaft is rocked, and an overload-magnet adapted to rock said shaft.

6. In combination, a system of doors, an. electromagnet controlling each door, means operated by each door for breaking the circuit of its controlling-magnet, a plurality of control-circuits each including a plurality of said magnets, a plurality of independentlymovable control-switches adapted to energize the several control-circuits, and automatic means for preventing the closing of any of said switches when the sum of the currents in the several control-circuits exceeds a predetermined amount.

7. In combination, a system of doors, an

electromagnet controlling each door, means operated by each door for breaking the circuit of its controlling-magnet, a plurality of control-circuits each including a plurality of said magnets a plurality of independentlymovable control-switches adapted to energize the several controlcircuits, a magnet in series with all of said control-circuits, and means controlled by said magnet for preventing the closing of any of said switches.

8. In combination, a system of electrically-controlled doors, a plurality of controlcircuits each controlling a plurality of doors, a plurality of independently-movable control-switches adapted to energize the several controlcircuits, and automatic means for preventing the closing of any of said switches when the sum of the currents in said controlcircuits exceeds a predetermined amount.

9. In combination, a system of electrically-controlled doors, a plurality of controlcircuits each controlling a plurality of doors, a plurality of independently-movable control-switches adapted to energize the several control-circuits, a magnet energized by a current proportional to the sum of the currents in said control-circuits, and means controlled by said magnet for preventing the closing of said switches.

In witness whereof I have hereunto set my hand this 28th day of December, 1905.

LAURENCE A. HAWKINS. 

